In high-voltage transmission power lines, corona and radio interference are typical phenomena acting on the power line hardware. Corona, which is an electrical discharge brought on by the ionization of a fluid (e.g., air) surrounding an electrically-charged conductor, generally occurs when the electric field around a conductor is high enough to form a conductive region, but not high enough to cause electrical breakdown or arcing to nearby objects. Radio interference (also called electromagnetic interference) is the conduction or radiation of a radio frequency energy that may disrupt or interfere with electromagnetic waves of the same wavelength. If not controlled, it poses serious electromagnetic interference to the system and its vicinity.
In a typical power transmission system with suspended power lines, hardware is included to suspend the conductor in the air and an insulator to insulate the conductor from the transmission tower (which may include a pole or a lattice tower, for example). The insulator is generally made of porcelain, glass, or another suitable material such as a composite polymer. The hardware supporting the insulator and coupling the insulator to the transmission power lines is typically made of aluminum, iron, or steel.
One or more corona rings (which may also be called anti-corona rings) may be included at or near the end of the insulator closest to the transmission power lines. The corona rings may, when exposed to a high voltage, distribute the electric field gradient such that the maximum of the electric field gradient is lowered, for example to a level below the corona threshold to prevent corona discharge. The corona rings may prevent electrical overstress in the insulating materials and may prevent deterioration of the insulating materials over time.
One disadvantage of currently-known hardware coupling or otherwise securing the insulator to a corona ring is the ability of the corona ring to be installed upside-down or in another improper orientation by an inexperienced technician. The improper installation of a corona ring may limit its effectiveness and cause the insulator to become electrically overstressed and/or cause the insulative materials to deteriorate over time.